Raul Miller wrote (Dec 28):
Anyways one basic problem is that J needs to know the
part of speech represented by [. and ]. before it
can parse expressions containing them.
For example, consider
-&*~ 9
0
3&*~ 9
177147
If you can figure out what these two examples do, you should
also see that the underlying meanings for some of the words
are entirely different, based on the parts of speech involved.
I'm afraid I don't see what you're getting at. Given that
f =. 1 : 'u&*~'
-f 9
0
3 f 9
177147
then
f =. [. & * ~
shouldn't present a problem.
Another contradiction for expressions involving
[. would be that we do not know if the line represents
an adverb or a conjunction.
f=:[.
Did you mean
f=: 1 :'u'
Or did you mean
f=: 2 :'u'
?
I would apply the simple rule that ]. always gives
a conjunction whether [. appears or not, but
otherwise [. gives an adverb.
Is there a problem here that I don't see ?
Jose Mario Quintana wrote (Dec 28):
. . . Incidentally, I do not consider myself an expert, not even
close (to put it mildly), in GUI explicit programming which is the
way jijs.ijs is
written,. However, I program by looking at patterns and modifying
them to get
what I want and I have added items to the jijs.ijs menu with very
little
effort. Look at jijs.ijs; you might be pleasantly surprised.
I'm afraid I haven't made my purpose very clear to you. I was
wanting to write, indeed I had partially written, a book to
introduce tacit J to ordinary people with a mild or greater
interest in numbers and no programming experience. For
this reason my description was of J as in effect a splendid
and simple calculator: a .ijx window and a simple alternation
of user keying in an expression and the J interpreter putting
back a response.
In this approach there is no place for diversions into compilation
or to jijs.ijs. The user needs only J primitives and tacit
definitions. At least such was my intention. That was why
the incompleteness of tacit J was so frustrating.
Writing the compiling verb might be another matter depending on what
your
proposal ‘really’ means. It seems to me that when you talk about a
“simple
way to do simple things” you actually mean some way very similar, if
not
exactly, to the enhancements that you have proposed. I whish you
plenty of luck
waiting for the mountain to come to you, so to speak (if you decide
to do so); I am
afraid you will need it, partly because I (as Raul) also think that
they do
not seem to conform to the J framework properly. Hence my suggestion
to try to
implement them instead by preprocessing chunks code. Again, I would
be
interested to see them in action.
Well, there's another example above. But really my basic
reasoning is that [ and ] are great as verbs that in effect
bring into a function (verb) expression the arguments of
that function; the user controls where the arguments are
used by placing [ or ] where those arguments are needed.
Therefore it is a simple analogy that [. and ]. could be used
to bring into an operation (adverb or conjunction) expression
the operands of that operation, the user controlling where the
operands are used by placing [. or ]. where those operands
are needed.
Is there some problem with this that I can't see ? It looks
straightforward to me.
Neville Holmes, P.O.Box 404, Mowbray 7248, Tasmania
Normal e-mail: [EMAIL PROTECTED]
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